11 Old Microsoft-Signed Linux UEFI Shims Could Let Attackers Bypass Secure Boot

Cybersecurity researchers have discovered 11 old, Microsoft-signed, Unified Extensible Firmware Interface UEFI applications that could be abused to bypass Secure Boot on most systems using the modern firmware standard. "An attacker exploiting one of these vulnerable applications can execute...

CVE-2026-21265

CVE-2026-21265 describes a Secure Boot bypass tied to expiration of Microsoft root certificates in the UEFI KEK/DB chain. Affected certificates include KEK CA 2011 (expires 2026-06-24), UEFI CA 2011 (expires 2026-06-27), and Windows Production PCA 2011 (expires 2026-10-19). The vulnerability aris...

Secure Boot Certificate Expiration Security Feature Bypass Vulnerability

Windows Secure Boot stores Microsoft certificates in the UEFI KEK and DB. These original certificates are approaching expiration, and devices containing affected certificate versions must update them to maintain Secure Boot functionality and avoid compromising security by losing security fixes...

Microsoft Certificate Authority Configuration for Citrix Endpoint Management

The primary intent of this article is to provide steps on how an admin can enable certificate based authentication for Citrix Endpoint Management in MSCA...

Microsoft Windows Unauthorized Digital Certificates Spoofing Vulnerability (2718704)

Microsoft Windows operating system is prone to a digital certificates spoofing vulnerability. SPDX-FileCopyrightText: 2012 Greenbone AG Some text descriptions might be excerpted from a referenced sources, and are Copyright C by the respective right holders. SPDX-License-Identifier: GPL-2.0-only...